Slide component

ABSTRACT

In an embodiment, in a slide component, dynamic pressure generation grooves  10  are provided on a sealing face of at least one of a pair of slide parts  4, 7  so as to be isolated with no communication from the sealed fluid side and the leakage side by land portions R of both the sealing faces, and a plurality of independently-formed minute recessed sections  11  is provided at positions on the sealing face IS between the dynamic pressure generation grooves  10  and the leakage side, the positions being separated in the radial direction from the dynamic pressure generation grooves. The slide component can make the sealing faces fluid-lubricant and low frictional and prevent leakage of a sealed fluid and incoming of dust to the sealing faces at the time of normal operation.

TECHNICAL FIELD

The present invention relates to slide components suitable for amechanical seal, a bearing, and other slide units for example. Inparticular, the present invention relates to slide components of sealrings in which a fluid lies on sealing faces to reduce friction andthere is a need for preventing fluid leakage from the sealing faces, forexample, an oil seal to be used for a turbocharger or aircraft enginegear box, a bearing, or the like.

BACKGROUND ART

In a mechanical seal serving as one example of the slide components,performances thereof are evaluated by a leakage rate, a wear rate, andtorque. In the prior art, the performances are enhanced by optimizingseal material and sealing face roughness of the mechanical seal, so asto realize low leakage, long life, and low torque. However, due toraising awareness of environmental problems in recent years, furtherimprovement in the performances of the mechanical seal is required, andthere is a need for technical development going beyond the boundary ofthe prior art.

Under such circumstances, for example, as a device to be utilized in anoil seal device for a rotating part such as a turbocharger, there is aknown device including a rotating shaft rotatably accommodated in ahousing, a disc shape rotor to be rotated together with the rotatingshaft, and a disc shape stationary body abutted with an end face of therotor for preventing leakage of oil from the outer peripheral side tothe inner peripheral side, in which an annular groove that generatepositive pressure by centrifugal force of a fluid is provided on anabutment face of the stationary body, so as to prevent the oil fromleaking out from the outer peripheral side to the inner peripheral side(for example, refer to Patent Document 1).

In addition, for example, there is a known seal device of a rotatingshaft that seals a poisonous fluid, the seal device including a rotatingring and a stationary ring attached to a casing together with therotating shaft, in which spiral grooves that catch and bring a liquid onthe low-pressure side toward the high-pressure side by rotation of therotating ring are provided on a sealing face of any of the rotating ringand the stationary ring in such a manner that ends on the high-pressureside are formed as dead ends, so as to prevent a sealed fluid on thehigh-pressure side from leaking out to the low-pressure side (forexample, refer to Patent Document 2).

In addition, for example, as a surface seal structure suitable forsealing a drive shaft of a turbocharger with respect to a compressorhousing, there is a known structure in which one of a pair ofcooperating seal rings is provided in a rotating constituent element andthe other seal ring is provided in a stationary constituent element,these seal rings have seal faces formed substantially in the radialdirection during operation, a seal gap for sealing outer regions of theseal faces with respect to inner regions of the seal faces is formedbetween the seal faces, a plurality of recessed sections separated inthe circumferential direction, the recessed sections being effective forfeeding a gas in is provided on at least one of the seal faces, therecessed sections are extended from one peripheral edge of the seal facetoward the other peripheral edge, and inner ends of the recessedsections are separated from the other peripheral edge of the seal facein the radial direction, so that a non-gas component in a gas mediumcontaining the non-gas component is sealed (for example, refer to PatentDocument 3).

CITATION LIST Patent Document

Patent Document 1: JP62-117360 U

Patent Document 2: JP62-31775 A

Patent Document 3: JP2001-12610 A

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

However, in the prior art described in Patent Documents 1 to 3 above,for example as shown in FIG. 9, on a sealing face 51 a of a stationaryring 51, leakage-side ends 53 a of spiral grooves 53 that catch andbring a fluid on the low-pressure fluid side (hereinafter, sometimesreferred to as the “leakage side”) toward the sealed fluid side(high-pressure fluid side) by rotation of a rotating ring 52 aredirectly open to the leakage side. Thus, in the vicinity of openingparts, dust may forcibly be pulled into the sealing faces by relativesliding between the sealing face of the stationary ring 51 and thesealing face of the rotating ring 52. The pulled dust is ground andsmashed by relative sliding of both the sealing faces so as to moreeasily come into a part between both the sealing faces. Thus, there is aproblem that surface damage such as wear of both the sealing faces ispromoted.

An objective of the present invention is to provide a component capableof making sealing faces of a pair of slide parts that relatively slideon each other fluid-lubricant and low frictional and preventing leakageof a sealed fluid and incoming of dust to the sealing faces at the timeof normal operation, so that contradictory functions of sealing andlubrication of the sealing faces are both improved.

Means for Solving Problem

In order to achieve the foregoing objective, a slide component accordingto a first aspect of the present invention includes a pair of slideparts that relatively slide on each other, one of the slide part being astationary-side seal ring and the other slide part being a rotating-sideseal ring, the seal rings having sealing faces formed in the radialdirection to seal leakage of a sealed fluid, characterized in that adynamic pressure generation groove is provided on the sealing face of atleast one of the pair of slide parts so as to be isolated with nocommunication from the sealed fluid side and the leakage side by landportions of both the sealing faces, and a plurality ofindependently-formed minute recessed sections is provided at positionson the sealing face between the dynamic pressure generation groove andthe leakage side, the positions being separated in the radial directionfrom the dynamic pressure generation groove.

According to this aspect, the slide component capable of making thesealing faces fluid-lubricant and low frictional and preventing incomingof dust mixed in the fluid on the leakage side to the sealing faces atthe time of normal operation, so that contradictory functions of sealingand lubrication of the sealing faces are both improved can be provided.The dynamic pressure generation groove is isolated from the sealed fluidside by the land portions, and the minute recessed sections are arrangedat the positions separated in the radial direction from the dynamicpressure generation groove and formed to be independent from each other.Thus, no leakage is generated even in a static state.

A slide component according to a second aspect of the present inventionincludes a pair of slide parts that relatively slide on each other, oneof the slide parts being a stationary-side seal ring and the other slidepart being a rotating-side seal ring, the seal rings having sealingfaces formed in the radial direction to seal leakage of a liquid or amisty fluid serving as a sealed fluid, characterized in that a dynamicpressure generation groove is provided on the sealing face of at leastone of the pair of slide parts so as to be isolated with nocommunication from the sealed fluid side and the leakage side by landportions of both the sealing faces, and a plurality ofindependently-formed minute recessed sections is provided at positionson the sealing face between the dynamic pressure generation groove andthe leakage side, the positions being separated in the radial directionfrom the dynamic pressure generation groove.

According to this aspect, the slide component capable of making thesealing faces fluid-lubricant and low frictional and preventing leakageof the liquid serving as the sealed fluid and incoming of dust existingin the fluid on the leakage side to the sealing faces at the time ofnormal operation, so that contradictory functions of sealing andlubrication of the sealing faces are both improved can be provided. Thedynamic pressure generation groove is isolated from the side of theliquid serving as the sealed fluid by the land portions, and the minuterecessed sections are arranged at the positions separated in the radialdirection from the dynamic pressure generation groove and formed to beindependent from each other. Thus, no leakage is generated even in astatic state.

A third aspect of the slide component of the present invention relatesto the first or second aspect, characterized in that the dynamicpressure generation groove is formed in a spiral shape to suction thefluid on the leakage side and pump the fluid to the sealed fluid side.

According to this aspect, the fluid on the leakage side is pumped to thesealed fluid side at the time of normal operation, so that the sealedfluid is prevented from leaking out to the leakage side.

A fourth aspect of the slide component of the present invention relatesto any of the first to third aspects, characterized in that theindependently-formed minute recessed sections are formed by dimples.

According to this aspect, manufacture can be more easily made.

A fifth aspect of the slide component of the present invention relatesto any of the first to third aspects, characterized in that theindependently-formed minute recessed sections are formed by herringbonegrooves.

According to this aspect, a larger dynamic pressure effect can beobtained.

A sixth aspect of the slide component of the present invention relatesto any of the first to third aspects, characterized in that theindependently-formed minute recessed sections are formed by groovesections that form Rayleigh step mechanisms.

According to this aspect, the groove sections can be efficientlyarranged, so that a larger dynamic pressure effect can be obtained.

A seventh aspect of the slide component of the present invention relatesto any of the first to sixth aspects, characterized in that the dynamicpressure generation groove is formed in such a manner that aleakage-side end is extended long in the circumferential direction incomparison to a sealed fluid-side end, and a leakage-side opening partis enlarged.

According to this aspect, the leakage-side end a of the dynamic pressuregeneration groove does not communicate with the leakage side, andincoming of dust mixed in the fluid on the leakage side to the dynamicpressure generation groove is suppressed, so that an effect of supplyingthe fluid to the dynamic pressure generation groove can be increased.

An eighth aspect of the slide component of the present invention relatesto any of the first to seventh aspects, characterized in that a fluidintroduction groove communicating with the sealed fluid side and notcommunicating with the leakage side is provided on the sealing face ofat least one of the pair of slide parts. Thereby, in a state where therotating-side seal ring is rotated at low speed such as the time ofstart-up, the liquid existing on the outer peripheral side of thesealing faces is actively introduced to the sealing faces so as tolubricate the sealing faces.

When the rotating-side seal ring is rotated at high speed such as normaloperation, the liquid introduced from the fluid introduction groove tothe sealing faces is discharged by centrifugal force. Thus, the liquiddoes not leak out to the inner peripheral side which is the leakageside.

Effect of the Invention

The present invention exhibits the following superior effects.

(1) The slide component including the pair of slide parts thatrelatively slide on each other, one of the slide parts being thestationary-side seal ring and the other slide part being therotating-side seal ring, the seal rings having the sealing faces formedin the radial direction to seal the leakage of the sealed fluid, ischaracterized in that the dynamic pressure generation groove is providedon the sealing face of at least one of the pair of slide parts so as tobe isolated with no communication from the sealed fluid side and theleakage side by the land portions of both the sealing faces, and theplurality of independently-formed minute recessed sections is providedat the positions on the sealing face between the dynamic pressuregeneration groove and the leakage side, the positions being separated inthe radial direction from the dynamic pressure generation groove.Thereby, the slide component capable of making the sealing facesfluid-lubricant and low frictional and preventing incoming of dust mixedin the fluid on the leakage side to the sealing faces at the time ofnormal operation, so that contradictory functions of sealing andlubrication of the sealing faces are both improved can be provided. Thedynamic pressure generation groove is isolated from the sealed fluidside by the land portions, and the minute recessed sections are arrangedat the positions separated in the radial direction from the dynamicpressure generation groove and formed to be independent from each other.Thus, no leakage is generated even in a static state.

(2) The slide component including the pair of slide parts thatrelatively slide on each other, one of the slide parts being thestationary-side seal ring and the other slide part being therotating-side seal ring, the seal rings having the sealing faces formedin the radial direction to seal the leakage of the liquid or the mistyfluid serving as the sealed fluid, is characterized in that the dynamicpressure generation groove is provided on the sealing face of at leastone of the pair of slide parts so as to be isolated with nocommunication from the sealed fluid side and the leakage side by theland portions of both the sealing faces, and the plurality ofindependently-formed minute recessed sections is provided at thepositions on the sealing face between the dynamic pressure generationgroove and the leakage side, the positions being separated in the radialdirection from the dynamic pressure generation groove. Thereby, theslide component capable of making the sealing faces fluid-lubricant andlow frictional and preventing the leakage of the liquid serving as thesealed fluid and incoming of dust existing in the fluid on the leakageside to the sealing faces at the time of normal operation, so thatcontradictory functions of sealing and lubrication of the sealing facesare both improved can be provided. The dynamic pressure generationgroove is isolated from the side of the liquid serving as the sealedfluid by the land portions, and the minute recessed sections arearranged at the positions separated in the radial direction from thedynamic pressure generation groove and formed to be independent fromeach other. Thus, no leakage is generated even in a static state.

(3) The dynamic pressure generation groove is formed in a spiral shapeto suction the fluid on the leakage side and pump the fluid to thesealed fluid side. Thereby, the fluid on the leakage side is pumped tothe sealed fluid side at the time of normal operation, so that thesealed fluid is prevented from leaking out to the leakage side.

(4) The independently-formed minute recessed sections are formed by thedimples. Thereby, the manufacture can be more easily made.

(5) The independently-formed minute recessed sections are formed by theherringbone grooves. Thereby, the larger dynamic pressure effect can beobtained.

(6) The independently-formed minute recessed sections are formed by thegroove sections that form the Rayleigh step mechanisms. Thereby, thegroove sections can be efficiently arranged, so that the larger dynamicpressure effect can be obtained.

(7) The dynamic pressure generation groove is formed in such a mannerthat the leakage-side end is extended long in the circumferentialdirection in comparison to the sealed fluid-side end, and theleakage-side opening part is enlarged. Thereby, the leakage-side end aof the dynamic pressure generation groove does not communicate with theleakage side, and incoming of dust mixed in the fluid on the leakageside to the dynamic pressure generation groove is suppressed, so thatthe effect of supplying the fluid to the dynamic pressure generationgroove can be increased.

(8) The fluid introduction groove communicating with the sealed fluidside and not communicating with the leakage side is provided on thesealing face of at least one of the pair of slide parts. Thereby, in astate where the rotating-side seal ring is rotated at low speed such asthe time of start-up, the liquid existing on the outer peripheral sideof the sealing faces is actively introduced to the sealing faces so asto lubricate the sealing faces.

When the rotating-side seal ring is rotated at high speed such as normaloperation, the liquid introduced from the fluid introduction groove tothe sealing faces is discharged by centrifugal force. Thus, the liquiddoes not leak out to the inner peripheral side which is the leakageside.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertically sectional view showing one example of amechanical seal according to a first embodiment of the presentinvention;

FIG. 2 is an enlarged view showing a sealing portion of a slidecomponent according to the first embodiment of the present invention, inwhich rotation center exists in the horizontal direction in a lower partof a paper plane;

FIG. 3 is a sectional view taken along the arrows A-A of FIG. 1;

FIG. 4 is an illustrative view for explaining a function of minuterecessed sections;

FIG. 5 is a view showing one of sealing faces of a slide componentaccording to a second embodiment of the present invention, the viewcorresponding to FIG. 3 of the first embodiment;

FIG. 6 is a view showing one of sealing faces of a slide componentaccording to a third embodiment of the present invention, the viewcorresponding to FIG. 3 of the first embodiment;

FIG. 7 is a view showing one of sealing faces of a slide componentaccording to a fourth embodiment of the present invention, the viewcorresponding to FIG. 3 of the first embodiment;

FIG. 8 is a view showing one of sealing faces of a slide componentaccording to a fifth embodiment of the present invention, the viewcorresponding to FIG. 3 of the first embodiment; and

FIG. 9 is an illustrative view for explaining the prior art: FIG. 9(a)is a vertically sectional view and FIG. 9(b) is a sectional view takenalong the arrows B-B.

DESCRIPTION OF EMBODIMENTS

Hereinafter, with reference to the drawings, modes for implementing thisinvention will be described with examples based on embodiments. However,regarding size, material, shape, and relative arrangement of constituentparts described in the embodiments, and the like, there is no intentionto limit the scope of the present invention only to those unlessspecifically and clearly described.

First Embodiment

With reference to FIGS. 1 to 4, a slide component according to a firstembodiment of the present invention will be described.

It should be noted that in the following embodiments, a mechanical sealserving as one example of slide components will be described as anexample. In the description, the outer peripheral side of the slideparts that form the mechanical seal serves as the sealed fluid side(liquid side or misty fluid side), and the inner peripheral side servesas the leakage side (gas side). However, the present invention is notlimited to this but can also be applied to a case where the outerperipheral side serves as the leakage side (gas side), and the innerperipheral side serves as the sealed fluid side (liquid side or mistyfluid side). Regarding a relationship in terms of high/low pressurebetween the sealed fluid side (liquid side or misty fluid side) and theleakage side (gas side), for example, the sealed fluid side (liquid sideor misty fluid side) may be high pressure and the leakage side (gasside) may be low pressure or vice versa, or the pressure may be the sameon both the sides.

FIG. 1 is a vertically sectional view showing one example of themechanical seal that is an inside mechanical seal for sealing a sealedfluid leaking out from an outer periphery of a sealing face toward aninner periphery, for example, lubricating oil used for a bearingsection. On the side of a rotating shaft 2 that drives an impeller 1 ofa compressor provided in a turbocharger, an annular rotating-side sealring 4 serving as one of the slide parts is provided via a sleeve 3 in astate where the rotating-side seal ring can be rotated integrally withthis rotating shaft 2, an annular stationary-side seal ring 7 serving asthe other slide part is provided in a housing 5 via a cartridge 6 in astate where the stationary-side seal ring is not rotated but can bemoved in the axial direction, and sealing faces S mirror-finished bylapping or the like closely slide on each other by means of a coiledwave spring 8 that biases the stationary-side seal ring 7 in the axialdirection. That is, in this mechanical seal, the rotating-side seal ring4 and the stationary-side seal ring 7 have the sealing faces S formed inthe radial direction to prevent the sealed fluid, for example, theliquid or the misty fluid (hereinafter, the liquid or the misty fluidwill be sometimes simply called as the “liquid”) from flowing out froman outer periphery of the sealing faces S toward an inner periphery onthe sealing faces S.

It should be noted that the reference sign 9 denotes an O ring to seal apart between the cartridge 6 and the stationary-side seal ring 7.

The reference sign 10 denotes dynamic pressure generation grooves andthe reference sign 11 denotes minute recessed sections. These will bedescribed later in detail.

In this example, a case where the sleeve 3 and the rotating-side sealring 4 are separate bodies is described. However, the present inventionis not limited to this but the sleeve 3 and the rotating-side seal ring4 may be formed as an integral body.

Material of the rotating-side seal ring 4 and the stationary-side sealring 7 is selected from the group consisting of silicon carbide (SiC)excellent in wear resistance and carbon excellent in self-lubrication.For example, the following combinations are available: both the ringsare made of SiC or one of the rings is made of SiC and the other is madeof carbon.

FIG. 2 is an enlarged view showing a sealing portion of the slidecomponent according to the embodiment of the present invention.

In FIG. 2, the dynamic pressure generation grooves 10 are provided onthe sealing face S of the rotating-side seal ring 4 so as to be isolatedwith no communication from the sealed fluid side and the leakage side byland portions R of the sealing faces of the rotating-side seal ring 4and the stationary-side seal ring 7. That is, in this example, thedynamic pressure generation groove 10 is provided only on the sealingface S of the rotating-side seal ring 4. The land portion R exists onthe leakage side and the sealed fluid side in the radial direction ofthe dynamic pressure generation groove 10. By bringing the land portionR of the sealing face S of the stationary-side seal ring 7 into slidingcontact with the land portion R of this rotating-side seal ring 4, thedynamic pressure generation groove 10 is isolated with no communicationfrom the sealed fluid side and the leakage side. In detail, the outerdiameter of the sealing face S of the stationary-side seal ring 7 on thesealed fluid side is set to be greater in the radial direction than asealed fluid-side end of the dynamic pressure generation groove 10 ofthe rotating-side seal ring 4, and the inner diameter of the sealingface S of the stationary-side seal ring 7 on the leakage side is set tobe smaller in the radial direction than a leakage-side end of thedynamic pressure generation groove 10. By bringing the land portion R ofthe sealing face S of the stationary-side seal ring 7 and the landportion R on the inner diameter side and the outer diameter side of thedynamic pressure generation groove 10 of the rotating-side seal ring 4into sliding contact with each other, the dynamic pressure generationgroove 10 is isolated with no communication from the sealed fluid sideand the leakage side.

As shown in FIG. 3 as well, the plurality of independently-formed minuterecessed sections 11 is provided on a sealing face IS between theleakage-side ends 10 a of the dynamic pressure generation grooves 10 andthe leakage side. The minute recessed sections 11 are arranged atpositions separated in the radial direction from the leakage-side ends10 a of the dynamic pressure generation grooves 10, and do notcommunicate with the dynamic pressure generation grooves 10.

In FIG. 3, the minute recessed sections 11 are formed bysubstantially-circular dimples 111. The dimples 111 are arranged atrandom, and size thereof, for example, the diameter may be identical ornon-identical.

In the present invention, the “minute recessed sections” indicate dentsformed on the flat sealing face S, and the shape thereof is notparticularly limited. For example, the planar shape of the dentsincludes various shapes such as a circular shape, an oval shape, anoblong shape, or a polygonal shape. The sectional shape of the dentsalso includes various shapes such as a bowl shape or a square.

A number of minute recessed sections 11 formed on the sealing face Salso have a function of holding part of the liquid intervening betweenthis sealing face S and the opposite sealing face that relatively slideas a hydrodynamic lubricant film so as to stabilize the lubricant film.

Each of the minute recessed sections 11 can be regarded as a sectionthat forms a Rayleigh step as shown in FIG. 4.

In FIG. 4, a Rayleigh step 11 a extending in the direction orthogonal toa cross-section of the figure is formed on the sealing face S (R) of therotating-side seal ring 4, and the sealing face S of the stationary-sideseal ring 7 is formed to be flat. When the rotating-side seal ring 4relatively moves in the direction shown by the arrow, the fluid lyingbetween both the sealing faces follows and moves in the arrow directionby viscosity thereof. At that time, due to existence of the Rayleighsteps 11 a, dynamic pressure (positive pressure) is generated. By thegeneration of this dynamic pressure, a gap between both the sealingfaces is slightly extended, and the fluid on the leakage side is easilysuctioned into the dynamic pressure generation grooves 10.

As shown in FIG. 3, the dynamic pressure generation grooves 10 are tosuction the fluid on the leakage side and pump the fluid to the sealedfluid side, and are formed for example in a spiral shape.

That is, since the land portion R exists on the leakage side and thesealed fluid side in the radial direction of the spiral dynamic pressuregeneration grooves 10, the dynamic pressure generation grooves 10 areisolated with no communication from the sealed fluid side and theleakage side. The dynamic pressure generation grooves are inclined in aspiral shape so as to exhibit an operation of pumping from theleakage-side ends 10 a toward the sealed fluid-side ends 10 b byrelative sliding between the rotating-side seal ring 4 and thestationary-side seal ring 7, so as to generate dynamic pressure(positive pressure) in the ends 10 b.

In a state where the rotating-side seal ring 4 is rotated at high speedsuch as normal operation, the spiral dynamic pressure generation grooves10 suction a gas from the leakage side while being helped by anoperation of the dimples 111, and generate dynamic pressure (positivepressure) in the vicinity of the sealed fluid-side ends 10 b. Thus, aslight gap is formed between the sealing faces S of the rotating-sideseal ring 4 and the stationary-side seal ring 7, so that the sealingfaces S are brought into a gas lubricant state and becomes very lowfrictional.

As described above, the substantially-circular dimples 111 are arrangedat the positions on the sealing face IS between the leakage-side ends 10a of the dynamic pressure generation grooves 10 and the leakage side,the positions being separated in the radial direction from theleakage-side ends 10 a of the dynamic pressure generation grooves 10 andformed to be independent from each other. Thus, the leakage-side ends 10a of the dynamic pressure generation grooves 10 and the leakage side donot directly communicate with each other. Therefore, incoming of dustmixed in the fluid on the leakage side to the dynamic pressuregeneration grooves 10 can be suppressed.

According to the configuration of the first embodiment described above,the following effects will be exhibited.

(1) The dynamic pressure generation grooves 10 are provided on thesealing face S of at least one of the pair of slide parts (sealing faceS of the rotating-side seal ring 4) so as to be isolated with nocommunication from the side of the liquid serving as the sealed fluidand the leakage side by the land portions R of both the sealing faces S,and the plurality of independently-formed dimples 111 that form theminute recessed sections 11 is provided at the positions on the sealingface IS between the dynamic pressure generation grooves 10 and theleakage side, the positions being separated in the radial direction fromthe dynamic pressure generation grooves 10. Thereby, the slide componentcapable of making the sealing faces fluid-lubricant and low frictionaland preventing leakage of the liquid serving as the sealed fluid andincoming of dust existing in the fluid on the leakage side to thesealing faces at the time of normal operation, so that contradictoryfunctions of sealing and lubrication of the sealing faces are bothimproved can be provided. The dynamic pressure generation grooves 10 areisolated from the side of the liquid serving as the sealed fluid by theland portions R, and the dimples 111 are arranged at the positionsseparated in the radial direction from the dynamic pressure generationgrooves 10 and formed to be independent from each other. Thus, noleakage is generated even in a static state.

(2) The dynamic pressure generation grooves 10 are formed in a spiralshape to suction the fluid on the leakage side and pump the fluid to theside of the liquid serving as the sealed fluid. Thereby, the fluid onthe leakage side is pumped to the side of the liquid serving as thesealed fluid at the time of normal operation, so that the liquid servingas the sealed fluid is prevented from leaking out to the leakage side.

(3) The independently-formed minute recessed sections 11 are formed bythe substantially-circular dimples 111. Therefore, manufacture can bemore easily made.

Second Embodiment

With reference to FIG. 5, a slide component according to a secondembodiment of the present invention will be described.

The slide component according to the second embodiment are differentfrom the slide component of the first embodiment in terms of aconfiguration of independently-formed minute recessed sections 11provided at positions on a sealing face between dynamic pressuregeneration grooves and the leakage side, the positions being separatedin the radial direction from the dynamic pressure generation grooves.However, the other basic configurations are the same as the firstembodiment. The same members will be given the same reference signs andduplicated description will be omitted.

In FIG. 5, a plurality of herringbone grooves 112 that form theindependently-formed minute recessed sections 11 is provided on asealing face IS between leakage-side ends 10 a of dynamic pressuregeneration grooves 10 and the leakage side. The herringbone grooves 112are arranged at positions separated in the radial direction from theleakage-side ends 10 a of the dynamic pressure generation grooves 10.

The planar shape of the herringbone grooves 112 is a substantially Lshape bent at right angle. Each of the herringbone grooves is arrangedso as to be open toward the upstream side on the sealing face and theplurality of herringbone grooves is provided in the circumferentialdirection.

Each of the minute herringbone grooves 112 forms a Rayleigh step asshown in FIG. 4. When a rotating-side seal ring 4 relatively moves inthe direction shown by the arrow, the fluid lying between both thesealing faces follows and moves in the arrow direction by viscositythereof. At that time, due to existence of Rayleigh steps 112 a of theherringbone grooves 112, dynamic pressure (positive pressure) isgenerated. By the generation of this dynamic pressure, a gap betweenboth the sealing faces is slightly extended, and the fluid on theleakage side is easily suctioned into the dynamic pressure generationgrooves 10.

According to the configuration of the second embodiment described above,the following effects will be exhibited.

(1) The dynamic pressure generation grooves 10 are provided on thesealing face S of at least one of the pair of slide parts (sealing faceS of the rotating-side seal ring 4) so as to be isolated with nocommunication from the side of the liquid serving as the sealed fluidand the leakage side by land portions R of both the sealing faces S, andthe plurality of independently-formed herringbone grooves 112 that formthe minute recessed sections 11 is provided at the positions on thesealing face IS between the dynamic pressure generation grooves 10 andthe leakage side, the positions being separated in the radial directionfrom the dynamic pressure generation grooves 10. Thereby, the slidecomponent capable of making the sealing faces fluid-lubricant and lowfrictional and preventing leakage of the liquid serving as the sealedfluid and incoming of dust existing in the fluid on the leakage side tothe sealing faces at the time of normal operation, so that contradictoryfunctions of sealing and lubrication of the sealing faces are bothimproved can be provided. The dynamic pressure generation grooves 10 areisolated from the side of the liquid serving as the sealed fluid by theland portions R, and the herringbone grooves 112 are arranged at thepositions separated in the radial direction from the dynamic pressuregeneration grooves 10 and formed to be independent from each other.Thus, no leakage is generated even in a static state.

(2) The dynamic pressure generation grooves 10 are formed in a spiralshape to suction the fluid on the leakage side and pump the fluid to theside of the liquid serving as the sealed fluid. Thereby, the fluid onthe leakage side is pumped to the side of the liquid serving as thesealed fluid at the time of normal operation, so that the liquid servingas the sealed fluid is prevented from leaking out to the leakage side.

(3) The independently-formed minute recessed sections 11 are formed bythe herringbone grooves 112. Therefore, a larger dynamic pressure effectcan be obtained.

Third Embodiment

With reference to FIG. 6, a slide component according to a thirdembodiment of the present invention will be described.

The slide component according to the third embodiment are different fromthe slide component of the first embodiment in terms of a configurationof independently-formed minute recessed sections 11 provided atpositions on a sealing face between dynamic pressure generation groovesand the leakage side, the positions being separated in the radialdirection from the dynamic pressure generation grooves. However, theother basic configurations are the same as the first embodiment. Thesame members will be given the same reference signs and duplicateddescription will be omitted.

In FIG. 6, a plurality of groove sections 113 a that form theindependently-formed minute recessed sections is provided on a sealingface IS between leakage-side ends 10 a of dynamic pressure generationgrooves 10 and the leakage side. The groove sections 113 a are arrangedat positions separated in the radial direction from the leakage-sideends 10 a of the dynamic pressure generation grooves 10. Each of thegroove sections 113 a is formed in an arc shape having fixed width inthe radial direction and extending in the circumferential direction, andforms a Rayleigh step mechanism 113 together with a radial deep groove12. The depth of the groove section 113 a is less than the depth of theradial deep groove 12.

Each of the minute groove sections 113 a forms a Rayleigh step as shownin FIG. 4. When a rotating-side seal ring 4 relatively moves in thedirection shown by the arrow, the groove sections suction the fluid fromthe leakage side via the radial deep grooves 12, and the suctioned fluidfollows and moves in the arrow direction by viscosity thereof. At thattime, due to existence of Rayleigh steps 113 b of the Rayleigh stepmechanisms 113, dynamic pressure (positive pressure) is generated. Bythe generation of this dynamic pressure, a gap between both the sealingfaces is slightly extended, and the fluid on the leakage side is easilysuctioned into the dynamic pressure generation grooves 10.

According to the configuration of the third embodiment described above,the following effects will be exhibited.

(1) The dynamic pressure generation grooves 10 are provided on thesealing face S of at least one of the pair of slide parts (sealing faceS of the rotating-side seal ring 4) so as to be isolated with nocommunication from the side of the liquid serving as the sealed fluidand the leakage side by land portions R of both the sealing faces S, andthe plurality of independently-formed groove sections 113 a that formthe minute recessed sections 11 is provided at the positions on thesealing face IS between the dynamic pressure generation grooves 10 andthe leakage side, the positions being separated in the radial directionfrom the dynamic pressure generation grooves 10. Thereby, the slidecomponent capable of making the sealing faces fluid-lubricant and lowfrictional and preventing leakage of the liquid serving as the sealedfluid and incoming of dust existing in the fluid on the leakage side tothe sealing faces at the time of normal operation, so that contradictoryfunctions of sealing and lubrication of the sealing faces are bothimproved can be provided. The dynamic pressure generation grooves 10 areisolated from the side of the liquid serving as the sealed fluid by theland portions R, and the groove sections 113 a are arranged at thepositions separated in the radial direction from the dynamic pressuregeneration grooves 10 and formed to be independent from each other.Thus, no leakage is generated even in a static state.

(2) The dynamic pressure generation grooves 10 are formed in a spiralshape to suction the fluid on the leakage side and pump the fluid to theside of the liquid serving as the sealed fluid. Thereby, the fluid onthe leakage side is pumped to the side of the liquid serving as thesealed fluid at the time of normal operation, so that the liquid servingas the sealed fluid is prevented from leaking out to the leakage side.

(3) The independently-formed minute recessed sections are formed by thesubstantially-arc shape groove sections 113 a that form the Rayleighstep mechanisms 113. Therefore, the groove sections 113 a can beefficiently arranged, so that a larger dynamic pressure effect can beobtained.

Fourth Embodiment

With reference to FIG. 7, a slide component according to a fourthembodiment of the present invention will be described.

The slide component according to the fourth embodiment are differentfrom the slide component of the first embodiment in terms of the shapeof dynamic pressure generation grooves. However, the other basicconfigurations are the same as the first embodiment. The same memberswill be given the same reference signs and duplicated description willbe omitted.

In FIG. 7, similar to the dynamic pressure generation grooves 10 of thefirst embodiment, a land portion R exists on the leakage side and thesealed fluid side in the radial direction of dynamic pressure generationgrooves 15. Thus, the dynamic pressure generation grooves 15 areisolated with no communication from the sealed fluid side and theleakage side. The dynamic pressure generation grooves are inclined in aspiral shape so as to exhibit an operation of pumping from leakage-sideends 15 a toward sealed fluid-side ends 15 b by relative sliding betweena rotating-side seal ring 4 and a stationary-side seal ring 7, so as togenerate dynamic pressure (positive pressure) in the ends 15 b. At thattime, in a state where the rotating-side seal ring 4 is rotated at highspeed such as normal operation, the spiral dynamic pressure generationgrooves 15 suction a gas from the leakage side while being helped by anoperation of dimples 111, and generate dynamic pressure (positivepressure) in the vicinity of the sealed fluid-side ends 15 b. Thus, aslight gap is formed between sealing faces S of the rotating-side sealring 4 and the stationary-side seal ring 7, so that the sealing faces Sare brought into a gas lubricant state and becomes very low frictional.

The independently-formed and substantially-circular dimples 111 arearranged between the leakage-side ends 15 a of the dynamic pressuregeneration grooves 15 and the leakage side while being apart from theends 15 a and the leakage side. Thus, the ends 15 a and the leakage sidedo not directly communicate with each other, so that incoming of dustmixed in the fluid on the leakage side to the dynamic pressuregeneration grooves 15 can be suppressed. At the same time, supply of thefluid on the leakage side to the dynamic pressure generation grooves 15is also suppressed.

Therefore, the dynamic pressure generation grooves 15 shown in FIG. 7are formed in such a manner that the leakage-side ends 15 a are extendedlong in the circumferential direction in comparison to the sealedfluid-side ends 15 b, and leakage-side opening parts are enlarged. Thus,an effect of supplying the fluid to the dynamic pressure generationgrooves 15 is increased.

The leakage-side ends 15 a of the dynamic pressure generation grooves 15are preferably extended to the upstream side in terms of increasing theeffect of supplying the fluid. Radial width of the leakage-side ends 15a may be similar to width of the sealed fluid-side ends 15 b.

According to the configuration of the fourth embodiment described above,the following effects will be exhibited in addition to the effects ofthe embodiments described above.

The leakage-side ends 15 a of the dynamic pressure generation grooves 15do not communicate with the leakage side, and incoming of dust mixed inthe fluid on the leakage side to the dynamic pressure generation grooves15 is suppressed, so that the effect of supplying the fluid to thedynamic pressure generation grooves 15 can be increased.

Fifth Embodiment

Next, with reference to FIG. 8, a slide component according to a fifthembodiment of the present invention will be described.

The slide component according to the fifth embodiment are different fromthe above embodiments in a point that fluid introduction grooves andpositive pressure generation mechanisms are provided on the sealed fluidside on a sealing face of at least one of a pair of slide parts.However, the other basic configurations are the same as the embodiments.The same members will be given the same reference signs and duplicateddescription will be omitted.

In FIG. 8(a), on a sealing face S of a rotating-side seal ring 4, fluidintroduction grooves 16 communicating with a peripheral edge on thesealed fluid side which is the outer peripheral side of the sealing faceS and not communicating with a peripheral edge on the leakage side whichis the inner peripheral side are provided.

One or more fluid introduction grooves 16 are arranged along theperipheral edge on the outer peripheral side and formed with the planarshape thereof being a substantially rectangular shape, communicate withthe sealed fluid side at the peripheral edge on the outer peripheralside of the sealing face S, and are isolated from the inner peripheralside by land portions R.

Positive pressure generation mechanisms 17 each of which includes apositive pressure generation groove 17 a communicating with acircumferentially downstream side part of the fluid introduction groove16, the positive pressure generation groove being shallower than thefluid introduction groove 16, are also provided. The positive pressuregeneration mechanisms 17 are to increase a fluid film between thesealing faces by generating positive pressure (dynamic pressure) so asto improve a lubricating performance.

Upstream side parts of the positive pressure generation grooves 17 acommunicate with the fluid introduction grooves 16 and are isolated fromthe outer peripheral side by the land portions R.

In this example, each of the positive pressure generation mechanisms 17is formed by a Rayleigh step mechanism including the positive pressuregeneration groove 17 a whose upstream side part communicates with thefluid introduction groove 16 and a Rayleigh step 17 b. However, thepresent invention is not limited to this but the point is that thepositive pressure generation mechanisms are only required to bemechanisms that generate positive pressure.

In FIG. 8(a), the planar shape formed by the fluid introduction groove16 and the positive pressure generation mechanism 17 is a substantiallyL shape.

Now, in a case where the rotating-side seal ring 4 is rotatedanti-clockwise, the liquid on the outer peripheral side is introducedfrom the substantially rectangular fluid introduction grooves 16 to thesealing faces, so as to lubricate the sealing faces S. At that time,positive pressure (dynamic pressure) is generated by the positivepressure generation mechanisms 17. Thus, the fluid film between thesealing faces is increased, so that the lubricating performance can befurther improved.

When the rotating-side seal ring 4 is rotated at high speed such asnormal operation, the liquid introduced from the fluid introductiongrooves 16 to the sealing faces is discharged by centrifugal force.Thus, the liquid does not leak out to the inner peripheral side which isthe leakage side.

FIG. 8(b) is different from FIG. 8(a) in a point that the shape of fluidintroduction grooves is different. However, the other points are thesame as FIG. 8(a).

In FIG. 8(b), on a sealing face S of a rotating-side seal ring 4, fluidintroduction grooves 18 communicating with a peripheral edge on thesealed fluid side which is the outer peripheral side of the sealing faceS and not communicating with a peripheral edge on the leakage side whichis the inner peripheral side are provided.

The fluid introduction grooves 18 are arranged along the peripheral edgeon the outer peripheral side, each of the fluid introduction grooves isformed by a fluid introduction section 18 a and a fluid ejection section18 b communicating only with the peripheral edge on the outer peripheralside of the sealing face S, and a fluid connection portion 18 cproviding communication between these sections in the circumferentialdirection, and the fluid introduction grooves are isolated from theinner peripheral side by land portions R.

In this example, the fluid introduction section 18 a and the fluidejection section 18 b are spaced by a fixed distance in thecircumferential direction and respectively linearly extended in theradial direction. Thus, the planar shape of the fluid introductiongrooves 18 is a substantially U shape.

Positive pressure generation mechanisms 17 each of which includes apositive pressure generation groove 17 a shallower than the fluidintroduction groove 18 are also provided in a part surrounded by thefluid introduction grooves 18 and the outer peripheral side. Thepositive pressure generation mechanisms 17 are to increase a fluid filmbetween the sealing faces by generating positive pressure (dynamicpressure) so as to improve a lubricating performance.

Upstream side parts of the positive pressure generation grooves 17 acommunicate with the fluid introduction sections 18 a and the fluidejection sections 18 b and the outer peripheral side are isolated fromeach other by the land portions R.

In this example, each of the positive pressure generation mechanisms 17is formed by a Rayleigh step mechanism including the positive pressuregeneration groove 17 a whose upstream side part communicates with thefluid introduction section 18 a of the fluid introduction groove 18 anda Rayleigh step 17 b. However, the present invention is not limited tothis but the point is that the positive pressure generation mechanismsare only required to be mechanisms that generate positive pressure.

Now, in a case where the rotating-side seal ring 4 is rotated clockwise,the liquid on the outer peripheral side is introduced from the fluidintroduction sections 18 a of the substantially U shape fluidintroduction grooves 18 to the sealing faces and discharged from thefluid ejection sections 18 b to the outer peripheral side. At that time,in a state where the rotating-side seal ring 4 is rotated at low speedsuch as the time of start-up, the liquid existing on the outerperipheral side of the sealing faces S is actively introduced to thesealing faces S so as to lubricate the sealing faces S. At that time,positive pressure (dynamic pressure) is generated by the positivepressure generation mechanisms 17. Thus, the fluid film between thesealing faces is increased, so that the lubricating performance can befurther improved.

When the rotating-side seal ring 4 is rotated at high speed such asnormal operation, the liquid introduced from the fluid introductiongrooves 18 to the sealing faces is discharged by centrifugal force.Thus, the liquid does not leak out to the inner peripheral side which isthe leakage side.

In FIG. 8(b), the planar shape of the fluid introduction grooves 18 is asubstantially U shape. However, the present invention is not limited tothis but the planar shape may be a shape in which the fluid introductionsection 18 a and the fluid ejection section 18 b cross each other on theinner diameter side, that is, a substantially V shape.

According to the configuration of the fifth embodiment described above,the following effects will be exhibited in addition to the effects ofthe first embodiment.

On a sealing face S of the rotating-side seal ring 4, the fluidintroduction grooves 16 or 18 communicating with the peripheral edge onthe sealed fluid side which is the outer peripheral side of the sealingface S and not communicating with the peripheral edge on the leakageside which is the inner peripheral side are provided. Thereby, in astate where the rotating-side seal ring 4 is rotated at low speed suchas the time of start-up, the liquid existing on the outer peripheralside of the sealing faces S is actively introduced to the sealing facesS so as to lubricate the sealing faces S. At that time, positivepressure (dynamic pressure) is generated by the positive pressuregeneration mechanisms 17. Thus, the fluid film between the sealing facesis increased, so that the lubricating performance can be furtherimproved.

When the rotating-side seal ring 4 is rotated at high speed such asnormal operation, the liquid introduced from the fluid introductiongrooves 16 or 18 to the sealing faces is discharged by centrifugalforce. Thus, the liquid does not leak out to the inner peripheral sidewhich is the leakage side.

The embodiments of the present invention are described above with thedrawings. However, specific configurations are not limited to theseembodiments but modifications and additions that are made within therange not departing from the gist of the present invention are alsoincluded in the present invention.

For example, although the example that the slide parts are used for anyof a pair of rotating and stationary seal rings in a mechanical sealdevice is described in the above embodiments, the slide parts can alsobe utilized as slide parts of a bearing that slides on a rotating shaftwhile sealing lubricating oil on one side in the axial direction of acylindrical sealing face.

In addition, for example, the outer peripheral side of the slide partsserves as the sealed fluid side (liquid side or misty fluid side), andthe inner peripheral side serves as the leakage side (gas side) in thedescription of the above embodiments. However, the present invention isnot limited to this but can also be applied to a case where the outerperipheral side serves as the leakage side (gas side), and the innerperipheral side serves as the sealed fluid side (liquid side or mistyfluid side). Regarding a relationship in terms of high/low pressurebetween the sealed fluid side (liquid side or misty fluid side) and theleakage side (gas side), for example, the sealed fluid side (liquid sideor misty fluid side) may be high pressure and the leakage side (gasside) may be low pressure or vice versa, or the pressure may be the sameon both the sides.

In addition, for example, although the case where the dynamic pressuregeneration groove 10 is a spiral groove is described in the aboveembodiments, the present invention is not limited to this but thedynamic pressure generation groove may be combination of a Rayleigh stepand an inverse Rayleigh step. The point is that the dynamic pressuregeneration groove is only required to be a mechanism that suctions thefluid on the leakage side and generates dynamic pressure (positivepressure).

In addition, for example, the dimples 111, the herringbone grooves 112,and the Rayleigh steps 113 b of the Rayleigh step mechanisms 113 aredescribed regarding the minute recessed sections 11 in the aboveembodiments. However, the present invention is not limited to this butfor example, the minute recessed sections may be parallel grooves ororthogonal grooves. Although the case where the shape of the dimples 111is a substantially circular shape is described in the above embodiments,the present invention is not limited to this but for example, the shapemay be an oval shape, an oblong shape, or a rectangular shape.

In addition, for example, the case where the dynamic pressure generationgrooves 15 whose leakage-side opening parts are enlarged are applied tothe first embodiment is described in the fourth embodiment. However, thepresent invention is not limited to this but the dynamic pressuregeneration grooves 15 can also be applied to the second and thirdembodiments needless to say.

In addition, for example, the case where the fluid introduction groovesand the positive pressure generation grooves provided on the sealedfluid side on the sealing face are applied to the first embodiment isdescribed in the fifth embodiment. However, the present invention is notlimited to this but the above grooves can also be applied to the second,third, and fourth embodiments needless to say.

REFERENCE SIGN LIST

-   -   1 Impeller    -   2 Rotating shaft    -   3 Sleeve    -   4 Rotating-side seal ring    -   5 Housing    -   6 Cartridge    -   7 Rotating-side seal ring    -   8 Coiled wave spring    -   10 Dynamic pressure generation groove    -   10 a Leakage-side end    -   10 b Sealed fluid-side end    -   11 Minute recessed section    -   111 Dimple    -   112 Herringbone groove (minute recessed section)    -   112 a Rayleigh step    -   113 Rayleigh step mechanism    -   113 a Groove section    -   113 b Rayleigh step    -   12 Radial deep groove    -   15 Dynamic pressure generation groove    -   16 Fluid introduction groove    -   17 Positive pressure generation mechanism    -   18 Fluid introduction groove    -   S Sealing face    -   IS Sealing face between leakage-side end of dynamic pressure        generation groove and leakage side    -   R Land portion

The invention claimed is:
 1. A slide component comprising a pair ofslide parts that relatively slide on each other, one of the slide partsbeing a stationary-side seal ring and the other slide part being arotating-side seal ring, wherein one of an outer peripheral side or aninner peripheral side of the pair of slide parts in a radial directionserves as a sealed fluid side, and the other of the outer peripheralside or the inner peripheral side of the pair of slide parts serves as aleakage side, the stationary-side and rotating-side seal rings havingsealing faces, respectively, formed in the radial direction to sealleakage of a sealed fluid from the sealed fluid side to the leakageside, characterized in that: a dynamic pressure generation groove isprovided on the sealing face of at least one of the pair of slide parts,and a land portion is provided on each of an inner-diameter side and anouter-diameter side of the dynamic pressure generation groove, thesealing face of the other of the pair of the slide parts has, in aradial direction, (i) an inner diameter which is set smaller than adiameter of an inner diameter-side end of the dynamic pressuregeneration groove, and (ii) an outer diameter which is set larger than adiameter of an outer diameter-side end of the dynamic pressuregeneration groove, the sealing face of the other of the pair of theslide parts is slidably in contact with the land portion on each of theinner-diameter side and the outer-diameter side of the dynamic pressuregeneration groove of the one of the pair of the slide parts, in a mannerthat, in a static state, the dynamic pressure generation groove isisolated from a sealed fluid side without fluid communication with thesealed fluid side and is isolated from the leakage side without fluidcommunication with the leakage side; and a plurality ofindependently-formed minute recessed sections is provided at positionson the sealing face between the dynamic pressure generation groove andthe leakage side, the positions being separated in the radial directionfrom the dynamic pressure generation groove.
 2. The slide component asset forth in claim 1, characterized in that: the dynamic pressuregeneration groove is formed in a spiral shape to suction the fluid onthe leakage side and pump the fluid to the sealed fluid side.
 3. Theslide component as set forth in claim 2, characterized in that: theindependently-formed minute recessed sections are formed by dimples. 4.The slide component as set forth in claim 2, characterized in that: theindependently-formed minute recessed sections are formed by herringbonegrooves.
 5. The slide component as set forth in claim 2, characterizedin that: the independently-formed minute recessed sections are formed bygroove sections that form Rayleigh step mechanisms.
 6. The slidecomponent as set forth in claim 2, characterized in that: the dynamicpressure generation groove is formed in such a manner that aleakage-side end is extended long in the circumferential direction incomparison to a sealed fluid-side end, and a leakage-side opening partis enlarged.
 7. The slide component as set forth in claim 2,characterized in that: a fluid introduction groove communicating withthe sealed fluid side and not communicating with the leakage side isprovided on the sealing face of at least one of the pair of slide parts.8. The slide component as set forth in claim 1, characterized in that:the independently-formed minute recessed sections are formed by dimples.9. The slide component as set forth in claim 8, characterized in that:the dynamic pressure generation groove is formed in such a manner that aleakage-side end is extended long in the circumferential direction incomparison to a sealed fluid-side end, and a leakage-side opening partis enlarged.
 10. The slide component as set forth in claim 1,characterized in that: the independently-formed minute recessed sectionsare formed by herringbone grooves.
 11. The slide component as set forthin claim 1, characterized in that: the independently-formed minuterecessed sections are formed by groove sections that form Rayleigh stepmechanisms.
 12. The slide component as set forth in claim 1,characterized in that: the dynamic pressure generation groove is formedin such a manner that a leakage-side end is extended long in thecircumferential direction in comparison to a sealed fluid-side end, anda leakage-side opening part is enlarged.
 13. The slide component as setforth in claim 1, characterized in that: a fluid introduction groovecommunicating with the sealed fluid side and not communicating with theleakage side is provided on the sealing face of at least one of the pairof slide parts.
 14. A slide component comprising a pair of slide partsthat relatively slide on each other, one of the slide parts being astationary-side seal ring and the other slide part being a rotating-sideseal ring, wherein one of an outer peripheral side or an innerperipheral side of the pair of slide parts in a radial direction servesas a sealed fluid side, and the other of the outer peripheral side orthe inner peripheral side of the pair of slide parts serves as a leakageside, the stationary-side and rotating-side seal rings having sealingfaces, respectively, formed in the radial direction to seal leakage of aliquid or a misty fluid serving as a sealed fluid from the sealed fluidside to the leakage side, characterized in that: a dynamic pressuregeneration groove is provided on the sealing face of at least one of thepair of slide parts, and a land portion is provided on each of aninner-diameter side and an outer-diameter side of the dynamic pressuregeneration groove, the sealing face of the other of the pair of theslide parts has, in a radial direction, (i) an inner diameter which isset smaller than a diameter of an inner diameter-side end of the dynamicpressure generation groove, and (ii) an outer diameter which is setlarger than a diameter of an outer diameter-side end of the dynamicpressure generation groove, the sealing face of the other of the pair ofthe slide parts is slidably in contact with the land portion on each ofthe inner-diameter side and the outer-diameter side of the dynamicpressure generation groove of the one of the pair of the slide parts, ina manner that, in a static state, the dynamic pressure generation grooveis isolated from a sealed fluid side without fluid communication withthe sealed fluid side and is isolated from the leakage side withoutfluid communication with the leakage side; and a plurality ofindependently-formed minute recessed sections is provided at positionson the sealing face between the dynamic pressure generation groove andthe leakage side, the positions being separated in the radial directionfrom the dynamic pressure generation groove.
 15. The slide component asset forth in claim 14, characterized in that: the dynamic pressuregeneration groove is formed in a spiral shape to suction the fluid onthe leakage side and pump the fluid to the sealed fluid side.
 16. Theslide component as set forth in claim 14, characterized in that: theindependently-formed minute recessed sections are formed by dimples. 17.The slide component as set forth in claim 14, characterized in that: theindependently-formed minute recessed sections are formed by herringbonegrooves.
 18. The slide component as set forth in claim 14, characterizedin that: the independently-formed minute recessed sections are formed bygroove sections that form Rayleigh step mechanisms.
 19. The slidecomponent as set forth in claim 14, characterized in that: the dynamicpressure generation groove is formed in such a manner that aleakage-side end is extended long in the circumferential direction incomparison to a sealed fluid-side end, and a leakage-side opening partis enlarged.
 20. The slide component as set forth in claim 14,characterized in that: a fluid introduction groove communicating withthe sealed fluid side and not communicating with the leakage side isprovided on the sealing face of at least one of the pair of slide parts.